Variable condenser



mi? Si, 1928.

R. T.WLLIAMS VARIABLE CONDENSER Filed mgm, 1925 INVENTOR Irl", 'fig the shaft f and is adapted to be connected with. a wire leerling ,to a source of electric current for connecting the series of plates P in the circuit of the receiving set. The plates P and P are thus shown to be opera0 tively connected together, the movable plates being rotatably mounted on the xed plates, and thev unit so :tar described isadapted to be attached 'to the rear of a panel A by ineens of a, pair or more of screws l2 connecting seid panel with the outer plate 2.

Ssid screws l2 have spacers i3 between the panel and the plate 2 for properly positioning the condenser with' respect to the panel. lxtcrually ofthe panel provide .the usuel 'form of tuning i beveled periphery el, with gradnations g ti creen, and an operating hub d Which-is usually lrnurledlor the purpose o readily turning the dial D for tuning purposes. Seid dial lies a central and internally eX- tended boss lil which is counter-bored to receive the extension i' of shaft li", end e set screwl is provided in the portion 0i of the dial and isiadnpted to be set against the end of tlie'cxtension 7 for lining the dial l) to the shaft l?. 'lhcouterportion of the dial is bored to receive the outer end of the inner shaft f, and. the end of portion d' is countcrsunlr at 16 toreceive a vernier button V which is provided with a metallic internally threaded bushing l? for detach.- ahly connecting the same to the threaded end of the shaft f at e point externally of 4 the dial, as shown in F1 2. i

Adjacent the "outer ce of the insulating disc E and also adjacent the inner -face or" tlieboss le on dial D, l provide metallic Washers W and W between which a coiled. spring H is mounted on the extension 7 of shaft F, and is held in tension.v The tendency of 'seid spring is to normally urge the dieloutwardly to a maximum extent, but permits the movement of the dial longitudiu nelly of its shaft against the tension of the spring in the direction of the panel A, from which said dial is normally spaced.

As shown in Fig; 2, one of the bolts `B v which hold the plates P together, is adapted to carry on one of its ends a clip 18 to which :a wire may be connected for connecting the stationary ypistes P in the receiving circuit. It will also be observed that 'seid plates P have semicircular cuts 19 in the upper and central portions thereof orproviding clearance between said plates and the portions 2O of the plates Ff; which are attached tof-the shaft F. Thus, it of .the plates P arevconnected together in the circuit and are in, metallic contact with the central,shait'fl which is adapted for connection with one side of the circuit, While the plates P are similarly connected together andere in metallic Contact with one o't the bolts adapted to be connected to the other dial D which has lvvill be observed that-ellsre side of the circuit. Plates l) end twfliewever, are insulated apart for olv/"lonsI pur poses.

Now, with the structure shown it will De noted that the plates P which are uniformly spaced apart, and the plates l which Bre correspondingly spaced ajjnut andl are adapted to rotate Withinz the spaces between the plates l), are so arranged inet any den sired relation may be attained bctw plates l endl by rotating the plo through the'mediuin oil the dial D, iv Y fixed to the sliat F, vthc nut G on said shaft serving to hold-all of the plates P und the spacers S in frictional engagement, so that all ofthe plates P will. be turned simultnconsly and to :i corresponding extent. v

As hereinbeiore stated, the rotation of the plates l with respect to the plates l?, regulates the capacity et the condenser for the dillerence in Wavelength of the. broadcasting station, and the plates l" `Jositionecl in spaced relation from the plates but nevertheless in neer relation thereto, so that the, electric current will bridge the space between the plates in the receiving op; eration.

lt is a well known fact that in the use and operation of radio receiving sets it is often veryl dillicult to tune out powerful stations or stations which are nearer to e receiving set then others, and frequently there will be a confusion in the reception and several experimentation I have found that when the )lates P are adjusted relative to the plates s'o as to vincremse the gap or space between the 'plates P and P longitudinally, am enabled to tune out all but a single station, or at least to vary the rer-.cptivity of the Conlicting stations so as to render the reception of e single station clearer and distinct. This is accomplished by the longitudinal ed jnstment of the plates P with respect to the plates P.,

een the stations can be heard simultaneously. By

are normally gli los

In operation, the dial D and plates P are first turned to the proper positionfor receiving rom a certain broadcasting station. Thereafter the dial D and plates-P' may be moved longitudinally againstthe tension of the spring H by moving the dial inwardly in the direction 'of the panel A.,

suicient clearance to provide for this movement being provided between the nut 6 on shaft F amd the member E. This initial 'movement of the dial D longitudinally will provide an index for the extent of movement uired for cutting out all but a single statiolngand thereafter the Vernier button V may be turned, effecting' a micrometer adjiiistment of the plates l, With res ect to the plates P.' llliis movement is e "ccted by reason ozt the tact that the central shaft fis nowrotatebly held `fin the member E, While tbe shaft l? is rotatz/Lble on tbc shaft j" end the'plates P and P and an ultimate and4 is also longitudinally movable I thereon. Thus, an initial and approximate relation of inner adjustment of thel same may be effect/ed for the purl ose described.

lili/'init l. o aim is:

l. A variable condenser including a series of stationary Jla'tes, a supporting panel therefor, spaced supporting plates, a sbazt xedly mounted on and insulated from said supporting plates, a hollow shaft rotatably vdial tor maintaining a dcsired'longitudinal adjustment of said movable plates.

2. A variable condenser including a frame, a plurality of spaced stationary plates mounted thereon, a longitudinally adjustable shaft insulated from and supported by the two end plates and adjustable relative thereto, a liolloiv'sha'ft encompassing said first mentioned shaft, a 'plurality of movable plates lixedly held on said hollow shaft and alternatinr with said stationary plates, a dial fixed to an end of said hollow shaft for rotating thc movable plates, and an operating member externally ot' said dial, adjustably connected with said first mentioned shaft for moving the movable plates longitudinally thereon and with respect to said stationary' plates.

2l. A variable condenser including a frame havinpr spaced supporting members, a plurality ol' spaced stationary plates mounted thcrcou, a 'longitudinally adjustable shaft extending through said supporting iuenihers and adjustable in one/of said meinber, a hol low shaft encompassing said first mentioned shaft, a plurality or movable plates xedly held on said hollow shaft and alternating with said stationary plates, a dial-fixed to an end of said hollow shaft for rotating the movable plates., an operating member erster nally of said dial, adjustably connected with. said rst mentioned shaft for movingtlae movable plates longitudinally thereon and with respect to said stationary lates, and spring means intermediate one o said supporting members and said dial for resilient y oldng the movable plates in adjusted pol sitions.

4. A variable condenser including a plurality of stationary plates and a plurality of movable plates eoaxially mounted with respect to each other, a frame for operably supporting the same, a rotatable 'hollow shaft journaled in said trarne for supporting said movable lates, a stationa shaft supportedon sai trame, and relativel adjustable operating members on the endg of said shafts for 'res actively effecting' the rotation of the movab e lates and the longitudinal adjustment ot' t e hollow shaft on the stationary shaft for longitudinally adjusting the movable lates,

- 5. The coin ination Witdh a panel of a variable condenser including a trarne, a set of vstationary plates and a set or movable plates spaced therefrom, a pair o Atelescopmg s rafts supported on said frame for supporting said movable plates, the outer shaft eing adjustable longitudinally on the inner shaft and separate coaxially mounted operating members at the ends of said shafts respectively for rotating,r and longitudinally adjusting the outer shaft on the inner shaft for the purpose described.

ROBERT T. WILIIAMS. 

